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Clinical Trial: Serotonin Receptors in Seizure Disorders
This study is currently recruiting patients.
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Purpose
Patients in this study will undergo PET scans (a type of nuclear imaging test) to look for abnormalities in certain brain proteins associated with seizures.
Studies in animals have shown that serotonin-a chemical messenger produced by the body-attaches to proteins on brain cells called 5HT1A receptors and changes them in some way that may help control seizures. There is little information on these changes, however. A new compound that is highly sensitive to 5HT1A, will be used in PET imaging to measure the level of activity of these receptors and try to detect abnormalities. Changes in receptor activity may help determine where in the brain the seizures are originating.
Additional PET scans will be done to measure the amount of blood flow to the brain and the rate at which the brain uses glucose-a sugar that is the brain's main fuel. Blood flow measurement is used to calculate the distribution of serotonin receptors, and glucose use helps determine how seizures affect brain function.
The information gained from the study will be used to try to help guide the patient's therapy and determine if surgery might be beneficial in controlling the patient's seizures.
| Condition | Treatment or Intervention |
|---|---|
| Partial Epilepsy | Drug: (O15) Water Drug: (F18) Fluorodeoxyglucose Drug: (F18) FCWAY |
MedlinePlus related topics: Epilepsy
Study Type: Observational
Study Design: Natural History
Official Title: PET Imaging of Serotonin Receptors in Seizure Disorders
Expected Total Enrollment: 75
Study start: June 21, 1999
Studies in experimental animals have suggested that: Serotonin is an anticonvulsant neurotransmitter in a number of seizure models. Its anticonvulsant action is mediated by activation of 5-HT(1A) receptors. Drugs with antiepileptic effects may release 5HT or block reuptake, and these mechanisms appear to be related to their therapeutic effect. 5HT(1A) receptors are abundant in regions such as entorhinal cortex, hippocampus, and temporal neocortex, where epileptogenic zones are frequently found. Considerable evidence from literature indicates that alterations in 5-HT(1A) receptors exist in experimental models of both generalized and complex partial seizures. There is little data on changes in 5-HT receptors in epileptic patients. Neuroimaging methods may provide a means for in vivo study. Using a new PET compound which is a highly selective 5-HT(1A) silent antagonist referred to as (18)FCWAY, we will attempt to detect abnormalities in serotonin receptors in vivo in patients with epilepsy. 65 patients with localization-related epilepsy and 10 normal T2-weighted clinical MRI) and 10 normal controls will have (18)FCWAY serotonin receptor studies (which include (15)H2O-CBF PET) will have (18)FCWAY PET and high resolution T1-weighted MRI for co-registration. (18)FDG-PET will be performed in the patients as part of seizure focus localization.
Eligibility
Genders Eligible for Study: Both
Accepts Healthy Volunteers
Criteria
Patients must have clinically documented partial seizures with consistent EEG evidence as defined by the 1981 International Classification of Epileptic Seizures, refractory to standard antiepileptic treatment for at least one year.
Patients will be in age ranges of 18 to 65.
Patients may be male or female. Female patients of child bearing potential will have a pregnancy test prior to the study to ensure that pregnant patients will not participate in the study. During the study, woman of child bearing potential must use a reliable method of birth control.
Three groups of patients will be scanned:
- 50 patients with EEg and clinical evidence for mesial temporal onset with either MRI findings of mesial temporal sclerosis (MTS) or dysplasia or normal MRI studies.
- 15 patients with apparent neocortical seizure foci.
- Ten normal controls will be included. Controls will be screened in the NINDS Clinical Epilepsy Section outpatient clinic, with physical examination, CBC urinalysis and blood chemistries. Controls with chronic illnesses, taking any medications, or who smoke will be excluded. They will be asked to abstain from alcohol for one week before the study.
EXCLUSION CRITERIA:
Patients younger than 18 years old will be excluded from the study.
Patients with a known treatable seizure etiology such as neoplastic or infectious disease will be excluded.
Patients with MRI findings consistent with brain tumors, trauma or AVMs will be excluded.
Patients with progressive neurologic disorders.
Patients with a history of significant medical or psychiatric disorders, or requiring chronic treatment with other drugs which can not be stopped, except for SSRIs.
Patients with cancer.
Patients not capable of giving an informed consent.
Patients who had seizure activity 24 hours prior to the study.
Location and Contact Information
Maryland
National Institute of Neurological Disorders and Stroke (NINDS), 9000 Rockville Pike, Bethesda, Maryland, 20892, United States; Recruiting
TTY 1-866-411-1010
More Information
Detailed Web Page
Publications
Biggs CS, Pearce BR, Fowler LJ, Whitton PS. Regional effects of sodium valproate on extracellular concentrations of 5-hydroxytryptamine, dopamine, and their metabolites in the rat brain: an in vivo microdialysis study. J Neurochem. 1992 Nov;59(5):1702-8.
Bradley PB, Humphrey PP, Williams RH. Evidence for the existence of 5-hydroxytryptamine receptors, which are not of the 5-HT2 type, mediating contraction of rabbit isolated basilar artery. Br J Pharmacol. 1986 Jan;87(1):3-4.
Busatto GF. Radioligands for brain 5-HT2 receptor imaging in vivo: why do we need them? Eur J Nucl Med. 1996 Aug;23(8):867-70. Review. No abstract available.
Record last reviewed: September 1, 2004
Last Updated: November 23, 2004
Record first received: November 3, 1999
ClinicalTrials.gov Identifier: NCT00001932
Health Authority: United States: Federal Government
ClinicalTrials.gov processed this record on 2005-04-08
Source: ClinicalTrials.gov
Cache Date: April 9, 2005
Resources
- Petit Mal Seizure (MayoClinic)

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